Photoelectron spectra and electronic structure of the transition metal dichlorides, MCl2(M = Cr, Mn, Fe, Co, Ni)

Abstract

The He(I) and He(II) photoelectron spectra of MCl₂(M = Cr, Mn, Fe, Co, Ni) are reported and interpreted by means of SW–Xα and ab initio molecular orbital calculations. The assignment of the ligand levels is accurately given by the use of Koopmans' theorem. The metal ionization energies are given incorrectly by the use of Koopmans' theorem and by the ΔSCF method, but are successfully predicted by a configuration interaction method that allows for orbital relaxation occurring upon ionization.